Universal smoke marking grenade for dry and inundated areas

ABSTRACT

A bouyant self righting, smoke marking grenade adapted for use either by firing from common infantry weapons or by hand initiation having, in cooperating combination, an outer waterproof flotation vessel closed on one end, a water permeable cup mounted on the closed end to provide a self righting capability by lowering the center of gravity of the floating grenade when the cup is filled with liquid; a smoke cannister, filled with a smoke producing pyrotechnic, supported in and spaced from the flotation vessel; an elongated tubular support member mounted in watertight relation across the open end of the flotation vessel and fixedly supporting the smoke cannister, the support member adaptable for mounting on the outside of certain weapons and the inside of others and having enough length and weight to provide drag stabilization when the grenade is fired; a double acting, spring controlled firing mechanism mounted in the support means communicating and in operable relation with the smoke cannister to activate the same and formed with smoke vents intermediate the smoke cannister and the interior of the support member, the firing mechanism being operable, manually by direct gas impingement or by inertial setback forces.

ll'nited States Patent 1 Grandy UNIVERSAL SMOKE MARKING GRENADE FORDRY AND INUNDATED AREAS [75] Inventor: Andrew J. Grandy, North Hills, Pa.

[73] Assignee: The United States of America as represented by the Secretary of the Army 22 Filed: Aug.31, 1971 21 Appl.No.: 176,450

Primary ExaminerVerlin R. Pendegrass Attorney-l-larry M. Saragovitz et al.

[ 5 7 ABSTRACT A bouyant self righting, smoke marking grenade [4 1 Apr. 10, 1973 adapted for use either by firing from common infantry weapons or by hand initiation having, in cooperating combination, an outer waterproof flotation vessel closed on one end, a water permeable cup mounted on the closed end to provide a self righting capability by lowering the center of gravity of the floating grenade when the cup is filled with liquid; a smoke cannister, filled with a smoke producing pyrotechnic, supported in and spaced from the flotation vessel; an elongated tubular support member mounted in watertight relation across the open end of the flotation vessel and fixedly supporting the smoke cannister, the support member adaptable for mounting on the outside of certain weapons and the inside of others and having enough length and weight to provide drag stabilization when the grenade is fired; a double acting, spring controlled firing mechanism mounted in the support means communicating and in operable relation with the smoke cannister to activate the same and formed with smoke vents intermediate the smoke cannister and the interior of the support member, the firing mechanism being operable, manually by direct gas impingement or by inertial setback forces.

8 Claims, 2 Drawing Figures UNIVERSAL SMOKE MARKING GRENADE FOR DRY AND INUNDATED AREAS The invention described herein may be manufactured, used and licensed by or for the Government for governmental purposes without the payment to me of any royalty thereon.

BACKGROUND OF THE INVENTION Smoke marking grenades are used for short duration screening, ground to air or ground to ground signalling or a combination of these uses. These grenades may be broadly described as either hand grenades or rifle grenades, based on their general configuration. If a proper adapter is available a smoke marking hand grenade can be launched from a rifle thus extending the effective range of its use. Floating, smoke marking, hand grenades are available, such as the grenades having the military designations XM63, XM64 and XM65. These grenades can be launched from the M16 and M14 rifle if the proper adapter is available. Many of the problems associated with grenades of the art stem from the fact that they are relatively specific in use, Because of this specificity it is necessary to carry a large number of different grenades and adapters to cover all situations. In addition, most grenades must be thrown some distance from the user before initiation to protect against possible injury to the user. The available floating grenades for use by infantry have a large open cavity in the interior to provide bouyancy thereby using up space which could be filled with smoke mixture. There is no specific self righting feature on these grenades. The weight of the fusing mechanism is depended upon to right the grenade whereby the smoke vent is directed upwardly. Of course, if a non-floating smoke grenade lands in an inundated area it will not function. Special grenades are necessary to fit on the M16 rifle, on the M14 rifle with special adapter, in the M79 grenade launcher or in the 81mm mortar. In all of these weapons special grenade launching cartridges are necessary. Rifle grenades, additionally, have impact fuzes and cannot be hand emplaced.

SUMMARY OF THE INVENTION The general purpose of this invention is to provide a grenade that has all of the advantages of similarly employed prior art devices and none of the above described disadvantages. To attain this, the present invention, a combination of outer flotation vessel with a water permeable self righting cup on one end, together with a smoke cannister mounted inside the vessel and spaced therefrom to provide bouyancy, a support member mounted in the vessel and communicating with the cannister and a firing mechanism mounted on the support member, provides a single grenade which is adaptable to be hand emplaced, hand thrown, fired from the M16 rifle, fired from the adapter used on the M14 rifle, fired from a 40mm grenade launcher and if a proper propulsion mechanism is used, fired from an 81mm mortar. This is done by fabricating the spigot support member with an inside diameter that will fit over the barrels of infantry rifles in common use, for example over the M16 flash hider or over the M14 adapter. The outside diameter of the spigot is fabricated to fit into the barrel of grenade launchers in common use such as the M-79. The outside diameter of the flotation vessel is made to correspond to the barrel size of mortars in common use such as the 81mm mortar. In addition since the grenade employs a setback type firing mechanism which can be activated by movement of the trigger on the spigot, the grenade can also be hand emplaced or hand thrown. Further, the smoke cannister can be completely filled with smoke composition as the bouyancy is contributed by the double walled casing. Also the self righting feature of this grenade adds little additional weight as it is simply a dynamic method of lowering the center of gravity by admitting water in a separate chamber in the nose of the grenade. This combination of an outer flotation vessel fitted with a self righting water permeable nose chamber containing an inner smoke cannister spaced from the vessel to cause bouyancy, on which is mounted an adaptable spigot and a double acting firing mechanism overcomes the disadvantages of the prior art.

An object of the present invention is to provide multiple capability of launching and emplacement for a single grenade.

Another object is to provide a floating grenade which has a multiple launch capacity.

Yet another object is to provide a grenade which has a self righting capacity which will insure that the smoke will emerge when the grenade is deployed in inundated areas.

Other objects and many of the attendant advantages of the present invention will be readily appreciated as the same become better understood by reference to the following detailed description when considered in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross'sectional view of the grenade assembly in the safe, uncocked position.

FIG. 2 is an enlarged, detailed, cross-sectional view of the firing assembly 41 as shown in FIG. 1.

Similar numerals refer to similar parts throughout both FIGS.

DESCRIPTION OF THE PREFERRED EMBODIMENT The entire grenade assembly as shown in FIGS. 1 and 2 is provided with a hollow waterproof flotation vessel 10 of a generally right circular cylindrical shape having a neck portion 12 on one end. The other end of the vessel terminates in a hollow hemispherical nose chamber 14 sealed off from the cylindrical portion of the vessel by a waterproof partitition 16. This chamber 14 has a plurality of holes 17 in its outer wall 18 to permit entry of water into the chamber thus altering the center of gravity of the grenade and providing a self righting capacity when the grenade is deployed in water.

An elongated right circular cylindrical spigot 20 having a first smaller axial bore 21 and a plurality of spaced annular rings 22 disposed around its outside and terminating in an annular shoulder portion 24 is mounted in the neck portion 12 of the vessel 10. An outwardly flared annular trigger 13 is slidably mounted on the shoulder portion 24 of the spigot 20 to provide a hand firing capacity for the grenade. The trigger 13 has two transverse safety pin holes 15 axially aligned to accommodate a slidably mounted safety pin 80. The spigot 20 has two axially, longitudinally extending, aligned hinge pin slots 23 to accommodate lengthwise movement along the spigot 20 of a hinge pin 78 fixedly held by the trigger 13, inwardly of the shoulder portion 24. The shoulder portion 24 is enlarged to form a second axial bore 26 coaxial with and communicating with the first smaller bore 21 at a point intermediate the ends of the shoulder portion 24. The second axial bore 26 is tapped to accommodate the threaded annular flange 56. The shoulder portion 24 is fixedly and coaxially mounted in the neck portion 12 of the vessel 10. The shoulder portion also has two axially aligned transverse holes 25 which communicate with the two safety pin holes 15 in the trigger 13 when the trigger 13 is mounted on the spigot 20.

The flotation vessel contains a hollow right circular cylindrical cannister 28, sealed at one end, and open at the other, in coaxial relationship to the vessel 10, disposed so that the sealed end is opposite but spaced from the waterproof partition 16 and of such size as to leave a sufficient air-space 30 between the vessel 10 and the cannister 28 to provide bouyancy for the grenade. The cannister 28 is provided with thin transverse layers of delay composition 31 and intermediate therebetween thick transverse layers of smoke composition 32, beginning distally from the partition 16 with the delay composition 31. A hollow metallic coaxial delay train housing 34 having a plurality of openings 36 one of each communicating with each of the layers of smoke composition 32 is located in the cannister 28. Delay composition 38 is disposed in the delay train housing 34 to provide a means of positive ignition of each of the smoke composition layers 32 without depending exclusively on normal propagation throughout the composition. A firing mechanism housing 40 is mounted in the open end of the cannister 28. This housing is of generally cylindrical shape having a large annular inwardly directed flange 42 thereby forming a bore 44 symmetrical and axially disposed in relation to the cannister. Extending outwardly lengthwise thereof and supported thereby is the firing assembly 41, shown in detail in FIG. 2, which includes therein a plurality of circumferentially radially disposed smoke vents 55 extending lengthwise and communicating with the smoke composition-delay filled cannister 38 on one end and the atmosphere on the other end.

The threaded firing pin support member 57 having a small bore 58, axially extending from one end to the other, is intermediate the smoke vent and is mounted in the partially tapped central bore 59 of the firing assembly 41. Which central bore 59 extends from one end to the other with an enlarged portion 61 thereby providing a shoulder 63. The tapped portion of central bore 59 is to accommodate the firing pin support member 57. The dual section firing pin 60 is slidingly disposed in the bores 58 and 59 and includes at one end a flange 65 terminating in a pointed striking portion 67. The other end of the pin 60 has a first transverse orifice 66 aligned with the safety pin holes in the trigger 13 and the holes 25 in the shoulder portion 24 of the spigot to accommodate the safety pin 80 and a second transverse orifice 68 aligned with the slots 23 in the shoulder portion 24 of the spigot 20 to accommodate the hinge pin 78. This end is supported by hinge pin 78 which is free to slide in slots 23 so that the firing pin is permitted to slide rearwardly and lengthwise of the assembly during either manual operation or setback. This relative rearward motion compresses spring 70 which is positioned between the flange 65 and the shoulder 63 around the firing pin 60 so as to cock it. Intermediate its ends the firing pin is made separable as by a shoulder latch break 76 so that when this shoulder latch clears the rear of the support member 57 it will separate and permit the forward pin portion to move forward under the action of the spring without any restriction being imposed by the hinge pin 78. The neck portion 46 of the firing mechanism housing 40 terminates in a threaded smaller annular flange 56 adapted to be mounted in the enlarged second axial bore 26 in the spigot 20. A primer cap 62 is located in the primer cup extending through the primer bore 48.

A hinge pin 78 having an outside diameter slightly smaller than the second transverse orifice 68 in the firing pin is mounted in this orifice 68, extending through the slot 23 in the spigot 20 and fixed to the trigger 13.

A manually removable safety pin 80 is slidably mounted through safety pin holes 15 in the trigger 13 and extending through the holes 25 in the shoulder 24 of the spigot 20 through the first transverse orifice 66 in the firing pin 60 to provide positive insurance against accidental firing.

In operation, safety pin 80 is removed manually, thereafter any force, which can cause sufficient relative motion between the trigger 13 and the spigot shoulder 24 to insure that shoulder latch 76 of the firing pin 60 will clear bore 58, will cause activation. This force can be applied manually by moving the trigger 13 relative to the spigot 20 or by the inertial forces of firing setback when the spigot 20 is fired from a rifle or from a grenade launcher or a mortar. The application of force to the trigger 13 while the spigot 20 is supported will cause relative motion between the trigger l3 and the spigot shoulder 24. The hinge pin 78 fixed to the trigger 13 will move rearwardly in the hinge pin slots 23. The firing pin 60 having the hinge pin 78 mounted therein in transverse hole 68 will move rearwardly in a fixed relationship to the hinge pin 78. This movement of the firing pin 60 will compress the spring 70 between the rearwardly moving flange and the shoulder 63. The latch 76 is so designed that when enough relative rearward movement has taken place it clears the surface of the bore 59. The tension of the spring will cause angular motion of the bottom portion of the pin 60 around the hinge pin 78 thus freeing the front portion of the pin. The compressed spring 70 will then cause forward movement of the front portion of the pin 60 by exerting force against the flange 65. This forward motion of the pin terminates when the pointed striking portion 67 hits the primer cap 62. The primer cap 62 being of ignitable, pressure sensitive material will ignite and transfer ignited material through the primer bore 48 into the delay composition 31 which in turn will cause initiation of the smoke mix layers 32 and emission of smoke through the smoke vents 55 after an initial delay. Normal propagation of combustion throughout the smoke layers 32 and delay layers 31 will usually result in complete combustion of the contained pyrotechnic. Delay composition 38, however, provides a secondary method for propagation as the smoke mix 32 burns as far as the first hole 36 in the delaytrain housing 34, the delay composition 38 will ignite and slowly, depending on its composition, burn to each succeeding hole 36 communicating with each smoke mix layer 32 thus providing a secondary means of ignition other than normal propagation. The burn time of the grenade can be varied by using a properly selected delay composition in delay layers 32. Any delay com position in use would be suitable with our invention for either delay 32 or delay 38 so long as it met the design requirements selected. For example, a mixture containing from about 4 to about 1 1 percent by weight boron and from about 89 to about 96 percent by weight barium chromate may be used. The smoke compositions can be any of the compositions known to the art. For example a mixture containing about 23 to 35 percent by weight sugar, about 20 to 35 percent by weight KCIQ, and about 30 to 54 percent by weight ofa suitable dye such as l methylamino anthraquinone, if a red smoke is desired, may be used.

After manual initiation of the grenade by pulling the trigger 13 the grenade may be thrown or hand emplaced. a

If the grenade is placed on the muzzle adapter of the M14 rifle or on the flash hider of the M16 rifle or in the 40mm grenade launcher or used in the 81mm mortar, the firing mechanism will be operated either by direct gas impingement or by inertial setback forces. The special cartridges used with this weapon in the M14 and M16 and 40mm launcher provide the necessary force to cause setback and in addition the gas pressure impinging on the bottom surface of the firing assembly 41 will cause propulsion of the entire grenade assembly. The spigot 20 is made long enough so that drag stabilization will stabilize the round without fins.

If the grenade lands in water the waterproof flotation vessel will keep it afloat due to the bouyant air chamber 30 contained within. The holes 17 in the nose chamber 14 admit water to alter the center of gravity of the grenade so that it floats with the spigot 20 upright.

Summarizing, the grenade of this invention employs a combination of an outer flotation vessel with a water permeable nose portion to provide a self righting feature. A smoke cannister filled with a smoke producing pyrotechnic is mounted inside the vessel and spaced from it to leave a buoyant space between them. A supporting spigot which has multiple launching capability is fixed to the vessel in communicating relationship with the cannister. A trigger is slidably mounted on the spigot to provide a capability for manual operation. A firing mechanism is mounted on the cannister between the cannister and the spigot and is fixed to the trigger so that relative movement of the trigger to the spigot will cock and activate the mechanism which then initiates the grenade. The size of the grenade components can be adapted to fit existing firearms. The smoke composition can be varied according to the desired results both as to color and duration.

It should be understood of course that the foregoing disclosure relates to only preferred embodiments of the invention and that numerous modifications or alterations may be made therein without departing from the spirit and the scope of the invention as set forth in the appended claims.

I claim:

1. A grenade comprisinglin combination: a. a hollow waterproof otation vessel having a neck portion open at one end,

b. a water permeable nose chamber of hemispherical shape mounted on the other end of said vessel, said nose chamber having a plurality of holes to provide a means of altering the center of gravity of said vessel to insure that the neck portion remains upright when the grenade is deployed in inundated areas,

0. smoke producing means supported in and spaced from said vessel,

d. hollow support means mounted across said open end of said vessel and fixedly supporting said smoke producing means therein and e. firing means mounted on said support means communicating and in operable relation with said smoke producing means to activate the same upon relative motion of said firing means and formed with smoke vents intermediate said smoke producing means and the interior of said hollow support means.

2. A grenade as defined in claim 1 wherein said vessel is of generally right circular cylindrical shape,

3. A grenade as defined in claim 1 wherein said smoke producing means is a cannister of generally right circular cylindrical shape open at one end containing a smokeproducing pyrotechnic therein, coaxially supported in and spaced from said flotation vessel to provide enough air space to impart bouyancy to said vessel.

4. A grenade as defined in claim 2 wherein said hollow support means being of generally right circular cylindrical shape and having a plurality of peripherally space annular rings is mounted in said neck portion and fixedly supports said smoke producing means.

5. A grenade as defined in claim 1 wherein said firing means includes:

a. a housing having said smoke vents formed lengthwise therein; and further includes a central bore having an intermediate enlarged portion;

b. a primer cap carried coaxially by said housing at one end thereof;

c. a firing pin slidingly disposed in said central bore,

in the path of said cap;

d. biasing means operatively coupled to said pin for impelling said pin toward said cap when released from compression and e. means for selectively compressing and releasing said biasing means.

6. A grenade as defined in claim 5 wherein said biasing means includes a helical spring disposed in said enlarged portion of said central bore, around said firing pm.

7. A grenade as defined in claim 5 wherein said compressing and releasing means includes an outwardly flared annular trigger mounted on said support means in operative relationship to said biasing means.

8. A grenade as defined in claim 5 wherein said firing pin includes a flange at one end terminating in a pointed striking portion adjacent said primer cap, and a shoulder latch break intermediate the ends of said fir ing pin. 

1. A grenade comprising in combination: a. a hollow waterproof flotation vessel having a neck portion open at one end, b. a water permeable nose chamber of hemispherical shape mounted on the other end of said vessel, said nose chamber having a plurality of holes to provide a means of altering the center of gravity of said vessel to insure that the neck portion remains upright when the grenade is deployed in inundated areas, c. smoke producing means supported in and spaced from said vessel, d. hollow support means mounted across said open end of said vessel and fixedly supporting said smoke producing means therein and e. firing means mounted on said support means communicating and in operable relation with said smoke producing means to activate the same upon relative motion of said firing means and formed with smoke vents intermediate said smoke producing means and the interior of said hollow support means.
 2. A grenade as defined in claim 1 wherein said vessel is of generally right circular cylindrical shape,
 3. A grenade as defined in claim 1 wherein said smoke producing means is a cannister of generally right circular cylindrical shape open at one end containing a smoke producing pyrotechnic therein, coaxially supported in and spaced from said flotation vessel to provide enough air space to impart bouyancy to said vessel.
 4. A grenade as defined in claim 2 wherein said hollow support means being of generally right circular cylindrical shape and having a plurality of peripherally space annular rings is mounted in said neck portion and fixedly sUpports said smoke producing means.
 5. A grenade as defined in claim 1 wherein said firing means includes: a. a housing having said smoke vents formed lengthwise therein; and further includes a central bore having an intermediate enlarged portion; b. a primer cap carried coaxially by said housing at one end thereof; c. a firing pin slidingly disposed in said central bore, in the path of said cap; d. biasing means operatively coupled to said pin for impelling said pin toward said cap when released from compression and e. means for selectively compressing and releasing said biasing means.
 6. A grenade as defined in claim 5 wherein said biasing means includes a helical spring disposed in said enlarged portion of said central bore, around said firing pin.
 7. A grenade as defined in claim 5 wherein said compressing and releasing means includes an outwardly flared annular trigger mounted on said support means in operative relationship to said biasing means.
 8. A grenade as defined in claim 5 wherein said firing pin includes a flange at one end terminating in a pointed striking portion adjacent said primer cap, and a shoulder latch break intermediate the ends of said firing pin. 